Don't overreport capital gains or underreport capital losses

When figuring capital gains and losses, be sure to increase what you paid for property by all permissible basis adjustments so that you minimize gains and maximize losses. Basis adjustments include broker's commissions and dividends reinvested in the case of stocks and mutual fund shares, and attorney's fees and other acquisition costs for real estate. If, for example, you fail to include the cost of shares you acquire through dividend reinvestment plans, you'll wind up paying twice on the same amount-once when you received the dividends and again when you sell the shares.